update podspec to v0.47
update podspec to v0.47

derrh/CanvasKit,nlambson/CanvasKit,nlambson/CanvasKit,instructure/CanvasKit,derrh/CanvasKit,derrh/CanvasKit,instructure/CanvasKit,nlambson/CanvasKit,nlambson/CanvasKit,derrh/CanvasKit,instructure/CanvasKit,instructure/CanvasKit